In railway track installations, the rails, attached to ties, are generally laid on a road bed on a granulate ballast layer, which is laterally embanked with a sufficient distance from the tie ends. It has been shown in practice that these embankments shift outward under the pressure of train traffic, so that there is the risk that the ballast layer under the ties will no longer guarantee sufficient support. For this reason, the embankments of such railway track installations are maintained at certain intervals, using suitable special machines which can move on the tracks. During this maintenance, the ballast material that has migrated outward is used again to form a sufficient embankment, at a certain angle of incline. Such maintenance work is labor-intensive and results in costs that are not insignificant.
From the magazine "Bautechnik", 1984, Issue 11, FIG. 6 on page 396, it is known to arrange sacks filled with a round ballast as reinforcement elements under the ties which carry the rails, and to attach them with reinforcement bands. Next to the rails and/or ties, an embankment of the type of a ballast layer can be seen. In such a process for supporting a railway track installation, obviously a special round ballast is required, which presumably is supposed to prevent the sharp edges of the ballast material from destroying the sacks. The disadvantage in such a process is the fact that the usual compacting of the ballast cannot be achieved in the sacks. It also does not appear possible to embed such sack-like reinforcement elements in a granulate ballast layer and to compact them with it.